Pump



Jan. 14, 1941.

S. WILTSE PUMP Filed June 11,A 1937 2 Sheets-Sheet l Jam/7er )M7/'Ja BYATTORN.

Jan. 14, 1941. s WlLTsE 2,228,714

PUMP Filed June 11, 1937 2 Smets-sheet 2 Patented Jan. 14, 1941 man PUMP

Sumner Wiltse, Detroit, Mich.

Application June 11, 1937, Seria-1 N e. 147,595

7 Claims.

This invention relates to reciprocating pumps of the type having adelivery or outiow stroke actuated by a resilient member, such as aspring, and a suction stroke induced against the action of saidresilient member by an actuating unit receiving its power from someoutside source. Such pumps are particularly adapted for use in pumpingfuel for internal combustion engines since the spring actuated outflowstroke renders the pump automatically operable in proportion to thedemand for fuel.

The greater number of present day pumps used in automobile practice aremechanically driven from some rotating part of the motor and, therefore,operate' at a speed proportional to that of the motor. It is true,however, that the speed of the motor is not necessarily properlycontrolling for the speed of the pump and often the speed is too great,pumping fuel at a rate which is not required and resulting inoverheating of the pumped fuel with consequent loss thereof byevaporation.

The use of a reciprocating pump having a spring actuated outflow strokeresults in automatically reducing the action of the pump when the amountof fuel delivered exceeds requirements, since when the pressure built upin the outflow line exceeds the spring pressure the pump will no longerreciprocate. However to gain full advantage from the use of this type ofpump it is important that sufficient capacity be available for peakrequirements and at the same time avoid pulsating now. This object,however, cannot be satisfactorily obtained by merely increasing the 1:5size of one reciprocating unit to increase capacity.

It is, therefore, a primary object of the present invention to provide apump having a primary pumping element with an outflow stroke so actuatedas to be resiliently responsive to outflow pressure as aforesaid, buthaving the added feature of a secondary pumping element controlled inits reciprocation by the primary pumping element vbut alternating insuction and delivery strokes whereby a more nearly constant flow may bemaintained at peak requirements while maintaining a practical rate ofreciprocation for both pumping elements.

As one .possible embodiment it is a further object to provide fuel pumpfor internal combustion engines with primary and secondary reciprocatingelements of the aforementionedcharacter having their suction strokesinduced by a source of suction made available by other means associatedwith the engine such for instance as (CL 10S- 152) operating inproportion to the amount of fuel 10 required. i

It is another objectto make available a reciprocating pump having dualpumping elements having suction strokes induced by suction and deliveryor outow strokes induced by spring 1.5

pressure or other resilient means, said elements being alternatelyconnected to atmosphere and to a source of suction by Valve meansoperated by the movement of one of said pumping elements. 2o

It is a further object to provide a pump with dual pumping diaphragins,each of which is actuated in its pumping stroke by resilient means, suchas a spring, and in its suction stroke by the operation of suction in achamber provided on 25 the side of each diaphragm away from the fluidbeing pumped, the suction admitted to each chamber being controlled by atwo way valve operated by the movement of one of the diaphragms. 3u

It is a further object to provide a duplex type of pump in which insteadof employing a double acting cylinder and piston, the duplex function isperformed by primary and secondary pumping elements but which are notphysically intercon- 3 nected and having valve means for controlling theaction of both pumping elements operated by the strokes of the primarypumping element.

The above and other objects of the invention will appear more fully fromthe following de- 4Q` tailed description of one possible mechanicalembodiment of the invention which has been found satisfactory in actualoperation, and by reference to the accompanying drawings forming a parthereof and wherein:

45 Fig. 1 is a vertical cross section through the pump showing thepumping chambers, the dual diaphragms, and the suction control valve.

Fig. 2 is a section taken on the line 2-2 of Fig. 1 and shows the inletand outlet conduits 50 lthrough the two pumping chambers, together withthe check valves required to effect the dual operation of the twopumping chambers.

Fig. 3 is a view taken substantially on the line 3 3 of Fig. 1 and showsa top view of the operat- 55 ing parts of the control valve foralternately connecting suction to the two diaphragms.

Fig. 4 is a section taken on the line 4-4 of Fig. 3 and shows a sideview of the operating parts of the suction control valve.

Fig. 5 is a section taken on the line 5--5 of Fig. 4 and shows a crosssection through the two valve units which control the alternateconnection of suction and atmosphere with the two pumping chambers.

Fig. 6 shows a modified form of the pump in which an auxiliary manuallyoperated mechanism is provided for alternately actuating the two pumpingelements in a suction stroke.

Referring to the drawings, particularly .to Fig. 1, a central pumpcasting I0 preferably circular in shape is provided with an inletconduit I I havin-gv suitable threaded connection flor a fuel pipe, notshown. 'Ilhis inlet conduit Il, in the form of a drilled hole, extendsinto the central portion of the pump casting I0 and communicates withtwo inlet check valves'designated generally by the reference charactersI2 and I3, see Fig. 2, -through Isuitable cross-drilled conduits I4 andI5. The inlet check valve I2 communicates with a lower pumping chamberI6 formed byra recess in the lower face of the ycentral pump cas-tingI0; While the inlet check valve I3 communicates with an upper, pumpchamber I1 formed by a similar recess in the top surface of the centralpump casting I0. The communicating opening from the check valve I2 tothe lo-wer pump chamber VI6 is shown Iat IB in Figs. 1 and 2, while thecommunicating :conduit to the upper pump chamber I1 is indicated by thefull lines at I9 in Fig. 1. The above described sylstem of vides yacommon inlet into the casting I0 with separate clieck valves I2 and I3opening into the pump chambers I6 and I1 respectively.

The detailed construction of both check valves I2 and I3 is similar, asshown in Fig. 2, there being a specially designedvscrew 2l with aprojecting end 22 for retaining a spring 23 which hold's a valve member24 against a seat formed at the eind of each o-f the conduits I4 and I5.Provision for assembly of the check valves is accomplished by drillingfrom the outside of the casting l0 and providing suitable threadstlherein for the screws 2I.

There are 'separate` outlets for both 'pump chambers I6 and I1, theoutlet from the lower pump' chamber I6 'being shown at 2-6 in Fig. 1and' Fig. 2, and the outlet from the upper `pump chamber I1 being shown`dotted at 21 in Fig. 1. The conduit 26 leading from the lower pumpchamber I6 :connects with the conduit 28 which leads into a main outletconduit 29 extending across the casting ID and' shown in both Figs. 1and 2. Another conduit 3I connects the conduit 21 from the upper pumpchamber I1 with the main outlet conduit 29.- Outlet check valves 32 anjd33 are provided for operation with the conduits 28 and3l respectively,thereby affording an outlet check valve from the upper and lower pumpchambers into the main outlet conduit 29. Both outlet check valves 32and 33 are of a construction similar to that used for the inlet checkvalves described above, a specially designed screw 34 with endprojection 36, spring 31 and valve member 38 being pro-vided for eachvalve. The outlet conduit 29 has suitable threads at its end forconnection of a fuel pipe, not shown.

A pumping diaphragm unit completes each of the pumping chambers I6 andI1, tlhe lower diaphragm being designated 'by the referenceVcharfl-anges being designated as inlet conduits proacter 39 and theupper diaphragm by the reference .character 40. Each of these diaphragmsis gripped between the flange formed on the edge of the central pumpcasting I0, and the iiange of a suction `and spring retaining chambermember 4I, for the lower pump chamber, and a similar member 42 for tlheupper pump chamber, the

43 and 44 respectively. Suitable screw connecting means -are providedaround the flanges 43 and 44 as indicated at 46 in Fig. 2. The lowerldiaphragm 39 has a stem 41 secured at its center by provision of twolarge washers 48 and 49 on opposite sides of the diaphragm 39, securelyfastened by threads in the end of the stem 41 and by a nut 5I. The lowercasting 4-I is of such shape as to form a chamber 52 and toretain aspring 53 therein. The stem 41 i's retained for reciprocating movementin a suitable guiding boss 54 extending into the chamber 52. One end ofthe spring 53 reacts against the lower end of the chamber 52 and theother end reacts against the washer 49 and tends to push the diaphragm39 upwardly. The lower end of the stem 41 is mounted to reciprocate in abearing 56 pro-vided in a lower cover member 51 'as shown in Fig. 1. Anotch 58 is turned in the stem 41 for operating a valve mechanism whichwill later be described in detail. A valve chamber 59 is formed belowchamber 52 and is connected therewith by an opening 6I. 'Ilhe valvechamber 59 is closed at its lower end by the lower 'cover member 51 inwhich there is mounted adual valve mechanism, as shown in Figs. 4 and 5.

Continuing with the vdescription of upper diaphragm 40 and its operatingspring, the said diaphragm 40 is secured between the flange 44 of thecasting 42 and the centr-al casting I9. A stem 62 is secured to thecenter of the diaphragm 40 by a pair of washers 63 and 64 on oppositesides of said diaphragm, the washers being held in place on the stem 62by a suitable nut such as shbwn at 65. In a manner similar to thatemployed for the lower unit, the Istem 62 is mounted for reciprocatingmovement in a boss 66 extending downwardly into the upper diaphragmoperating chamber 61 which is formed in the casting 42. As shown in Fig.1, the chamber 61 is of such shape as to retainV a spring 68, one end ofwhich reactsv against the upper end of the chamber land the opposite endreacts against the washer 64 and tends to force the diaphragm 40downwardly. A conduit 13 leads from the lower valve unit to the chamber61. It is lthrough this conduit that suction is p-rovided for theactuation ofthe upper pumping unit in a manner which will appear morefully later in this description.

The fitting 69 shown at the top of Fig. 1 is for the purpose of closingthe opening provided for the reciprocating stem 62 and also when removedthis member 69 serves as a handle ior manual operation of the top pump`chamber unit. The attachment of the handle is accomplished by threadingthe screw threaded end 1-I of fitting 69 into the opening 1l2 madeavail-able when the fitting 69 .is removed. With the fitting 69 thusmounted a manual movement thereof in up and down `direction actuates thediaphragm 46 to manually operate the top half of the pump.

Proceeding now with the description of the two way valve unit shown indetail in Figs. 1, 3, 4 and 5, there is shown in Fig. 5 an opening at 14for connecting a supply pipe from a source of suction. The drilledconduit 16, shown in Fig. 5, affords a communicating passage for thesuction into chamber 59 when the valve positions are as shown in Fig.through the opening l1. The 1 andr 5. With the pump parts and toggleleveri necessary valve members are carried by plugs 8l, unit in thepositions shown in Fig. 1, the valve S2 as shown in Fig. 5, threadedinto the cover 5l' stems 83 and 8B will be held in the position shown bytwo threaded openings 18 and i9 provided in in Fig. 5 so that suctionmade available at 14 will 5 the 'cover 5l. The plug 8i has a valve seatproexhaust' air from the lower pump chamber 52 5 vided at each of itsends and carries a valve stem thru opening El', chamber 59, opening 'Hand 83 with suitable valve closure members, 81! and 85 conduit 16. Thelower pumping diaphragm 39 at its ends. The stem 83 is of sufiicientlength is sho-wn at the beginning of its suction stroke in so that thedistance between the `valve closure Fig. 1 and as the suction is appliedin the cham- 10 members 8d and 35 is greater than the length of ber 52the diaphragm 39 operates to perform its 10 the plug 8i Also the stem 83is' of less diameter downward or suction stro-ke. The stem 41 is carthanthe drilled opening 86 in the plug 8i, in ried with the diaphragm 39'andmoves the toggle which the stem is slidably mounted. Radial ports memberSi downward by contact with yoke |02, 86a (Fig. 4) connect drilledopening 36 with and near the end of the suction stroke the toggle AODEP-ling i6 (Fig. 5) through annular Space Wb uni-t will snap to theopposite position. When 15 (Fig. 4). Therefore, when the valve member 83this happens the position of member 96 will push. is in the upwardposition as shown in Fig. 5, the the valve stems 33 and 83 downwardlyand will lower valve closure 84 is sealed while the upper' connect thesuction at 'it thru conduits 76, 8T, closure is unsealed and the suctionline is thus 93 and i3 to exhaust air from the upper pump allowed tocommunicate with the chamber 59' chamber 6l. At the same time change inthe po- 20 through the opening Ti'. However, when the sition of closuremember 9| at the end of stem 88 member e3 is in the downward position,the will connect chambers 59', 52 with atmospheric lower closure 8d isopened and the suction comchamber 82a thru conduit 90. munica-tes withconduit El below the valve plug It is understood that the reciprocationof the 2518i while the valve member S5 has closed the diaphragms 39 orliti, in their respective pumping 20 opening TI from communication withthe `charnchambers i5 and Il', produces inflow of luid by ber 59. 'I'heother valve plug 82 shown in Fig. 5 action of the respective inlet checkvalves I2 and is similarly provided with a central hole 89 in i3 (Fig.2) when the direction of movement of which the valve stem 83reciprocates. A chamber said diaphragme 39 or @il is such as to increase'82a is form-ed between the lower face of the the volume of thechambersit or H. Conversely, 30 valve plug 82 and a closure plug 82h, this:chamwhen the direction of movement of the diaber Eid being open to theatmosphere thru a phragms 39 or 40 is in a direction to reduce theconduit 9d shown in Figs. 1 and 5. A valve volume of the pumpingchambers i6 or I1, the closure member Si is secured at the end of theresult will be an outflow of the iluid through the l stem S3 withsurfaces so shaped that when stem outlet 29 by action of the respectiveoutlet check 35 68 is in its downward position a conduit 89, leadvalves32 and 33 (Fig. 2).

ing to chamber 5S, is open to the atmospheric It is apparent that theaction of diaphragms chamber 3a while conduit 92 leading to upper 39 and40 is alternating and the action of the dipump chamber 'i is closed.However, with the aphragm 40 is indirectly controlled by the move- 8S isclosed and conduit 92 is ope-n to the atis directly attached. mosphericchamber 82a, thus supplying atmos- It is also to be noted that one -ofthe most impheric pressure to the upper pump chamber 6l portantadvantages of this type of pump is that through conduits 93 and i3. Eachof the valve the springs are acting against the resistance to stems 88and 8S project upwardly as shown in outilow of the fluid being pumped.In other 40 Fis. 4 and are Connected together by a pin 2t, words, whenthe resistance to outflow becomes which proicots through a toggle levermember greater than the force exerted bythe spring 53 on 9S, as shown inFigs. 1, 3 and 4. Another toggle the lower pumping diaphragm the pumpwill no lever member Si' is mounted on a post QS, and longer exert apumping stroke to force fluid into the two toggle members 95 and Si areoperatively the line, In this manner the pumping actionis 50 Connectedby a member 99 Which fits in JGWO momentarily stopped when theconsumption of notches in their ends aS Shown in Fg- 1` The fuel isreduced and there is no continuous pumpmembers E36 and 9i are alsoConnected by a Spring ing with its attendant heating and evaporation oflili and are so positioned that movement of the the fuel such as occursin many continuously re- *e* yoked end H32 of the toggle member Si willcause Ciprocai-,ing pumpe With the use, however, of a change in positionof the member B6 from the they Combination of the upper diaphragm 40upward location Shown in Fis- 1 to an opposite working alternately withthe lower diaphragm 39 dovv'nWard DoStOl. This movement S a QUICK asuincient pumping ability isy assured at all times Snap When the togglepasses a demte point when a large quantity of fuel is required. This 60(lo in its movement. It is understood that the yoke Cooperativealternating action is assured because i W2 ts around the notch 58 if theStem SO that the action of the upper diaphragm is controlled dfwnwardmovement of the spem Q? .Wm will in its action by the lower diaphragm insuch the toggle assume the opposite position to that manner that theupper pumping diaphragm is shown 1n Fig. l and close the valve i5 sothat .h G5' suction is shut oif from the lower chambers 52 Opera'tufe toperfqrm a plfmpmg strek? While t e 65 and 59 and admitted to the upper,pump Chamber lower diaphragm 1s perfoimmg lts suction stroke. M It isalso noted that atmospheric pressure is It 1s apparent that the use ofdouble alternating admitted to the opposite chamber, not connecteddaphragms Controlled by one 0f them makes with the suction line, by themovement of the Practical the 115e 0f this WDG 0f Dump in many 70 valvestem 88 also actuated by the toggle Q6. conditions of operationrequiring a considerable t0. The manner in which the pump operates is asrange of fuel consumption, since the `double follows: A line from someunit producing sucstroke assures a sufficient capacity to take caretion, such for instance, as described in my coof all demands Whileavoiding pulsating flow. pending application, Serial'No. 147,595, ledJune The modified form off pump shown in Fig. 6 is so valve stem Sli inits upward position, the conduit ment of diaphragm 39 to which the valvecontrol 40 1l, 1937, is connected at 'lf3 as. shown in Figs.A providedwith mechanism for manual operation m upwardly also 4.. in addition tothe automatic operation which has been previously described. In thismodification the invention is particularly adapted for use in aircraftwork where it is often necessary to have a hand operated pump forsupplying fuel because of the usual practice of running the motorsentirely out of fuel at certain times to reduce re hazard. It isintended that the pump shown in Fig. 6 be located in or near the pilotscompartment so that handle |25 will be in a convenient position foroperation. The central pump casting |26 shown in Fig. 6 is of identicalconstruction with the central pump casting shown on Fig. 1 of thedrawings. In fact, the entire mechanism for automatic operation and thedual diaphragm construction is the same as in the pump shown in Fig. 1.However, there is added in the construction shown in Fig. 6 necessaryconnecting parts to secure a manual operatinglinkage, denoted generallyby the reference character |21, to stems |28 and |29 which are connectedto actuate with upper and lower pumping diaphragms |30 and |3| in asuction stroke. For the purpose of manually actuating the top of thediaphragm |30 a hollow shaft |32 is mounted to reciprocate in a suitableboss |33 projectingfrom the top of the pump and suitably threaded toreceive a nut |34 adapted to retain conventional packing |35. The hollowshaft |32 projects above the nut |34 and is pivotally mounted to a lever|36, the end of which is secured to a link |31. The hollow shaft |32fits over and surrounds the stem |28 which is connected to the upperdiaphragm |30. A pin |38 is secured to the stem |28 and projectsoutwardly therefrom into slots |39 and |40 in the sides of the hollowshaft |32. It will be noted that this means of connection of the stem|28 to the hollow shaft enables the diaphragm |30 t0 be automaticallyreciprocated by the suction mechanism when the shaft |32 is in theposition as shown in Fig. 6 since the relative position of the slot |40and the pin |38 allows reciprocation of the stem |28. However, whenthe-lever |36 is pulled away from the pump, i. e. upwardly, as shown inFig. 6, it will pull the diaphragm |30 against the action of thediaphragm spring which normally urges the pump in a direction for adelivery stroke. In other words, the actuation of the lever |36 providesmanual means for producing a suction` stroke, the delivery strokes stillbeing spring actuated as in automatic operation.

A similar connecting means for manual operation is provided at the lowerside of the pump for connection to the stem |29 in the form of a hollowshaft |4|, a nut |42, a lever |43 and a link |44, a pin |45 secured tostem |29 being provided to operate in the slots |46 and |41. It isapparent that the actuation of the lever |43 away from the pump willeffect a suction stroke of the diaphragm |3| against the delivery strokespring as previously mentioned in connection with the upper diaphragmoperating lever |36.

For the purpose of normally holding the levers |36 and |43 in theposition nearest the pump so that the slots in the hollow shafts |32 and4| will not interfere with automatic operation of the pump, a tensionspring |48 is provided vto connect the two ends of the levers |36 and|43 and therefore to normally urge them toward each other therebyproducing the desired position of the levers. 'For the purpose ofproviding mechanism for placing the pump in condition for manualoperation a pair of links |49 and |50 are provided with a pivotalconnection |5|, the combined lengths of the links |49 and |50 beinggreater than the distance between the ends of the levers |36 and |43when in the position nearest the pump as held by the tension of spring|48. Therefore, when the handle |25 is pushed toward the pump as shownin Fig. 6 to straighten out the links |49 and |50 the result is tospread the ends of the levers |36 and |43 away from each other againstthe tension of the spring |48. The position of the slots in the hollowshafts |32 and |4| will then be such that up and down movement of thehandle |25 will alternately actuate the diaphragms |30 and |3| in asuction stroke, the delivery stroke in each case being accomplished bythe spring which normally operates the diaphragms in this stroke.

Although I have described my invention as applied to a particularillustrative combination found practical in actual use, it is apparentthat various changes and modifications may be made withoutl departingfrom the fundamental principles herein disclosed. I do not desire tolimit myself to the specific embodiments but rather to the scope of thefollowing claims.

I claim:

1. In a suction operated pump, a primary pumping element, a secondarypumping element movable independently of said primary pumping element, acommon inlet and a common outlet conduit for both of said pumpingelements, a suction valve operated by said primary pumping elementcontrolling alternate admission of suction to both elements through saidconduits, and a second valve interconnected with said suction valve forcontrolling alternate admission of atmospheric pressure to said primaryand secondary pumping elements.

2. In a, pump, a central pump casting having a recess on twosidesthereof, inlet and outlet check valves mounted in said casting andconnecting with said recesses, independently movable diaphragms coveringeach of said recesses to form two pumping chambers, members shaped toform suction chambers on the opposite side of said diaphragms from saidrecesses and attached to said central casting in a manner such 1 astogrip the edges of said diaphragms, springs mounted in said suctionchambers to normally urge said diaphragms inwardly of said pumpingchambers, conduit connections to said pumping chambers including anatmospheric vent and a suction connection to said chambers, and valvemeans to alternately .subject said suction chambers to said suctionconnection and to atmospheric pressure whereby said diaphragms arealternately flexed outwardly against the action of said springs toproduce suction strokes in said pumping chambers.

3. In a pump, a pair of independently movable pumping elements,resilient means fo-r actuating said pumping elements for outflowstrokes, suction operated means for actuating said pumping elements forsuction strokes, conduit connections to said pumping elements includingan atmospheric vent for each of said elements, a source of suction, atwo way valve connected to be operated by movement of said pumpingelements to alternately connect said source of suction with said pair ofpumping elements through said conduit connections and to alternatels7open said atmospheric vents thereby to produce alternate operation ofsaid pumping elements.

4. In a pump, a reciprocable primary pumping element for a delivery oroutflow stroke, suction operated mechanism for actuating said primarypumping element in a suction stroke against the action of said resilientmeans, a secondary reciprocable pumping element movable independently ofsaid primary pumping element, conduit connections to each of saidpumping elements including an atmospheric vent for each of saidelements, and means under control of said primary pumping element tocause said suction operated mechanism to operate said secondary pumpingelement in `a suction stroke and to alternately subject said pumpingelements to suction and atmospheric pressure through said conduitconnections.

5. In a pump, a pair of independently movable pumping elements, suctionoperated means actuating said pumping elements for suction strokes,resilient means actuating said pumping elements for outo-W strokes, asource ofsuction, a member connected to lreciprocate with one of saidpumping elements, a two-Way valve connected thereto, conduit connectionsto each of said pumping elements including an atmospheric vent for eachof said elements from said two- Way valve to said suction operatedpumping elements, a toggle for operating the said two-way valve, aprojection from said toggle contacting said reciprocating member wherebysaid two-way valve is operated when said reciprocating member and saidpumping element complete a predetermined stroke thereby to alternatelyoperate said pair of suction operated pumping elements through saidconduit connections and to alternately subject said pumping elements toatmospheric pressure thru said atmospheric vent.

6. In a pump la primary pumping element having a delivery strokeactuated by spring pressure, a housing around said pumping elementforming a suction chamber, a source of suction, a valve member includingan atmospheric vent for connecting said source of suction or atmosphericpressure to said suction chamber to operate said pump for a suctionstroke against the action of said spring at'the end of said springactuated delivery stroke, a secondary pumping element, movableindependently of said primary pumping element, a housing around saidsecondary pumping element forming a suction mvv,

chamber, a Valve member including an atmospheric vent for connectingsaid secondary pumping element with said source ofv suction oratmospheric pressure to actuate said secondary pumping element in asuction stroke, a member actuated by said primary pumping elementwhereby said valve is actuated to connect said source of suction withsaid secondary pumping element at the end of the suction stroke of saidprimary pumping element. v

7. In apump of the type in which the delivery or outflow stroke isactuated by a spring `pressed element characterized by a primary pumpingelement and a secondary pumping element movable independently of saidprimary pumping element, said secondary pumping element alternately setin operation for a delivery stroke at the end of the delivery stroke ofsaid primary pumping element, and mechanism comprising a member actuatedby said primary pumping element for controllingthe operation of both ofsaid elements.V

SUMNER WILTSE.

